Table 2.

Mineral status of beef calves supplemented at two different levels of trace minerals (Cu, Se, and Zn) prior to weaning for 84 days.

		Treatments 1
Item	Year 4	Control	Super	SEM	p-Value
Initial Cu, mg/kg 2		120	122	12.2	0.90
Initial Se, mg/kg 2		1.09	1.13	0.086	0.69
Initial Zn, mg/kg 2		209	213	17.3	0.81
Weaning Cu, mg/kg 3	Year 1	67	53	16.4	0.52
	Year 2	127	167	16.4	0.08
Weaning Se, mg/kg 3		1.07	1.00	0.077	0.54
Weaning Zn, mg/kg 3		158	138	10.6	0.18

¹ Approximately 84 days prior to weaning, 24 calves/year (Angus × Hereford) were randomly assigned to one of two treatments (d0), Control: trace mineral supplementation (Cu, Se, and Zn) was provided based on current guidelines of nutrient requirements for beef cattle (NASEM, 2016; 10.0, 0.10, and 30.0 mg/kg of DM, respectively, for Cu, Se, and Zn); or Super: trace mineral supplementation was provided above the current guidelines of nutrient requirements for beef cattle (NASEM, 2016; 20.0, 0.20, and 60.0 mg/kg of DM, respectively, for Cu, Se, and Zn). ² Initial liver samples were collected on d0 of the study. Samples were sent to an analytical laboratory for mineral analyses (Michigan State University, Animal Health Diagnostic Laboratory, Lansing, MI, USA; Reference range: Cu: 40–650 mg/kg; Se: 0.60–3.30 mg/kg; Zn: 90–500 mg/kg). ³ A second liver sample was collected at weaning to evaluate the effects of trace mineral supplementation through the mineral status of calves. ⁴ Effects of year (p < 0.001) and treatment × year (p = 0.09) were observed for Cu concentration at weaning.